what causes crohn's disease

Crohn's disease is caused by a combination of factors, including genetic predisposition, abnormal immune system responses, environmental influences, and potentially bacterial factors. The exact cause remains unknown, but it is believed that in people genetically susceptible to the disease, their immune system mistakenly attacks the cells in the digestive tract, leading to chronic inflammation. Several genes have been linked to Crohn's disease, and environmental factors such as smoking and living in developed, urban areas also contribute to risk. Diet and stress can worsen symptoms but are not causes of the disease. The immune response in Crohn's is atypical, involving both innate and adaptive immunity, but it is not considered an autoimmune disease in the classical sense. Family history significantly elevates risk, with many patients having relatives with the disease.